Viral mitigation throughout all phases of biopharmaceutical manufacturing processes is an increasingly strict requirement established by international or national regulatory bodies in order to prevent viral contaminants in the application of biopharmaceuticals for therapeutic or non-therapeutic purposes. Several methods have been employed to inactivate and/or remove large or small, enveloped or non-enveloped viral particles from biopharmaceutical product compositions. Examples of such methods include filtration (e.g., 20 nm filtration, Q membrane chromatography, depth filter technology), heat (e.g., high temperature short time (HTST) pasteurization), chemical (e.g., addition of solvents—detergents or chemical agents), or radiation (e.g., ultraviolet or gamma-ray irradiation). These methods have been used primarily downstream in the biopharmaceutical manufacturing process due to their low throughput and/or high cost. Viral inactivation of cell culture media input into a biopharmaceutical manufacturing process, where up to 20,000 L or more are processed per day, would be prohibitive in terms of time and cost with existing methods. Some methods, such as ultraviolet C (UVC) irradiation, are challenging to apply to biopharmaceutical manufacturing processes, because, unlike in, for example, water treatment, over-exposure of the media (particularly media containing serum) can be detrimental, and therefore the radiation dose needs to be delivered uniformly to the media and controlled to within a relatively narrow range. An additional challenge for ultraviolet irradiation of media, particularly media containing serum, is that the UV transmittance in the UVC range (e.g., at 254 nm) of the media is substantially lower than the UV transmittance of, for example, water, in this wavelength range. In addition, it is desirable that devices used in high throughput biopharmaceutical manufacturing contain components that are amenable to cleaning and sterilization (e.g., clean-in-place (CIP) and steam-in-place (SIP) procedures). Therefore, there is a need for methods and apparatuses which enable high throughput viral inactivation of low transmittance liquid media for biopharmaceutical and other applications.